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Long-term patch dynamics in the community shaped by bivalves, barnacles, ascidians and red algae: multiple foundation species in the White Sea shallow subtidal. Eugene Yakovis Anna Artemieva Michael Fokin Marina Varfolomeeva Natalia Shunatova St.-Petersburg State University, Russia.
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Long-term patch dynamics in the community shaped by bivalves, barnacles, ascidians and red algae: multiple foundation species in the White Sea shallow subtidal
EugeneYakovis Anna ArtemievaMichaelFokin Marina VarfolomeevaNatalia ShunatovaSt.-Petersburg StateUniversity, Russia
Facilitation by foundation species shapes many terrestrial and benthic communities Communities with multiple functionally different foundation species are poorly studied
Locations: 12 m deep Site 1 and 15 m deep Site 2 Site 1 65° 01.2’N 35° 39.7’E Site 2 65° 00.7’N 35° 41.7’E The White Sea
Species diversity in and around EPs unstructured sediment H’=2.62±0.02 (55 cm2 cores) 101 mobile species (78 polychaetes) epibenthic patches H’ = 2.28±0.04 (24±1 cm2 patches) 119 mobile species (72 polychaetes) 111 sessile species (64 bryozans)
Biomass in and around EPs unstructured sediment wet weight of macrobenthic organisms 91 g/m2 epibenthic patches wet weight of macrobenthic organisms 745 g/m2
Overall species diversity H’ = 3.36±0.06 250 species in total (16 x 1 m2 frame) 117±7 species per 1 m2 frame
Total weight of epibenthic organisms within the patches based on different substrate type
Live Serripes groenlandicus stays under the sediment surface and never has sessile organisms attached
Sessile organisms can utilize a shell only when a clam dies
Sessile organisms can utilize a shell only when a clam dies Site 1: 1.8±0.4 unfouled valves of Serripes groenlandicus per m2 on the sediment surface Site 1: 6.7±2.9 live individuals of Serripes groenlandicus per m2
Most sessile organisms live on secondary biogenic substrates (% individuals)
Principal secondary space providers are barnacles and their empty shells, ascidians and red algae
These are 15 top frequent associations between sessile organisms and substrates …
Most live barnacles Balanus crenatus are found on primary substrate and conspecifics
Most ascidians Styela spp. are found on barnacles and their empty shells
As a result, epibenthic patches with following structure types are frequent:
The observed variation in structure of epibenthic patches: (i)results from patch dynamics or (ii) is just a product of spatial heterogeneity and variable recruitment ? predictions from (ii): > the structure of patches would not depend much on their age > the age-dependent variation of structure would not match one observed in EPs
Number of initially empty Serripes shells exposed S = 34.4 ± 0.8 cm2
Relative areas of principal substrates: shells, live barnacles, dead barnacles, ascidians and red algae by exposure term (shell area as 1) 9-10 yrs 7-8 yrs 5-6 yrs 1-2 yrs 3-4 yrs
Relative abundance of sessile organisms (% ind.) on shells, live barnacles, dead barnacles, ascidians, red algae and other substrates by exposure term 9-10 yrs 7-8 yrs 5-6 yrs 1-2 yrs 3-4 yrs
Mean LogE Shannon diversity of epibenthic assemblages on shells, live barnacles, dead barnacles, ascidians, red algae and other substrates by exposure term 9-10 yrs 7-8 yrs 5-6 yrs 1-2 yrs 3-4 yrs
nMDS of natural and experimental EPs on weights of ascidians, live and dead barnacles, red algae and Shannon diversity (stress=0.08) w/o substrate on Serripes shells on live snails on other substrates
nMDS of natural and experimental EPs on weights of ascidians, live and dead barnacles, red algae and Shannon diversity 1-2 yrs
nMDS of natural and experimental EPs on weights of ascidians, live and dead barnacles, red algae and Shannon diversity 3-4 yrs
nMDS of natural and experimental EPs on weights of ascidians, live and dead barnacles, red algae and Shannon diversity 5-6 yrs
nMDS of natural and experimental EPs on weights of ascidians, live and dead barnacles, red algae and Shannon diversity 7-8 yrs
nMDS of natural and experimental EPs on weights of ascidians, live and dead barnacles, red algae and Shannon diversity 9-10 yrs
nMDS of natural and experimental EPs on weights of ascidians, live and dead barnacles, red algae and Shannon diversity 1-10 yrs 1-2 3-4 5-6 7-8 9-10
The observed variation in structure of epibenthic patches: (i)results from patch dynamics or (ii) is just a product of spatial heterogeneity and variable recruitment ? predictions from (ii): > the structure of patches would not depend much on their age > the age-dependent variation of structure would not match one observed in EPs
The observed variation in structure of epibenthic patches: (i)results from patch dynamics or (ii) is just a product of spatial heterogeneity and variable recruitment ? predictions from (ii): > the structure of patches would not depend much on their age > the age-dependent variation of structure would not match one observed in EPs
The observed variation in structure of epibenthic patches: (i)results from patch dynamics or (ii) is just a product of spatial heterogeneity and variable recruitment ? predictions from (ii): > the structure of patches would not depend much on their age > the age-dependent variation of structure would not match one observed in EPs
The observed variation in structure of epibenthic patches: (i)results from patch dynamics or (ii) is just a product of spatial heterogeneity and variable recruitment ? predictions from (ii): > the structure of patches would not depend much on their age > the age-dependent variation of structure would not match one observed in EPs
Credits Alexander Tcherenkov Nadezhda Tcherenkova Alexey Grishankov Alexandra Yakovis Dmitry Tomanovsky Funding: RFBR grants № 02-04-50020-a, 05-04-48927-a, 05-04-63041-k, 06-04-63077-k, 06-04-58536-z, 06-04-58537-z, 07-04-10075-k, 07-04-08366-z, 08-04-01373-a, 08-04-10109-k, 09-04-10092-k, 10-04-08011-z
a shell exposed for 9 yrs